[PATCH 3/6] mini-os/x86-64 entry: code refactoring; no functional changes

[Xu Zhang <xzhang@cs.uic.edu>]

Re-arrange assembly code blocks so that they are in called
order instead of jumping around, enhancing readability.
Macros are grouped together as well.

Signed-off-by: Xu Zhang <xzhang@cs.uic.edu>
---
 extras/mini-os/arch/x86/x86_64.S |  118 +++++++++++++++++++-------------------
 1 files changed, 59 insertions(+), 59 deletions(-)

diff --git a/extras/mini-os/arch/x86/x86_64.S b/extras/mini-os/arch/x86/x86_64.S
index addb7b1..79e893f 100644
--- a/extras/mini-os/arch/x86/x86_64.S
+++ b/extras/mini-os/arch/x86/x86_64.S
@@ -36,6 +36,22 @@ hypercall_page:
         .org 0x3000
 
 
+#define XEN_GET_VCPU_INFO(reg)	movq HYPERVISOR_shared_info,reg
+#define XEN_PUT_VCPU_INFO(reg)
+#define XEN_PUT_VCPU_INFO_fixup
+#define XEN_LOCKED_BLOCK_EVENTS(reg)	movb $1,evtchn_upcall_mask(reg)
+#define XEN_LOCKED_UNBLOCK_EVENTS(reg)	movb $0,evtchn_upcall_mask(reg)
+#define XEN_TEST_PENDING(reg)	testb $0xFF,evtchn_upcall_pending(reg)
+
+#define XEN_BLOCK_EVENTS(reg)	XEN_GET_VCPU_INFO(reg)			; \
+                    			XEN_LOCKED_BLOCK_EVENTS(reg)	; \
+    				            XEN_PUT_VCPU_INFO(reg)
+
+#define XEN_UNBLOCK_EVENTS(reg)	XEN_GET_VCPU_INFO(reg)			; \
+                				XEN_LOCKED_UNBLOCK_EVENTS(reg)	; \
+    			            	XEN_PUT_VCPU_INFO(reg)
+
+
 /* Offsets into shared_info_t. */                
 #define evtchn_upcall_pending		/* 0 */
 #define evtchn_upcall_mask		1
@@ -46,6 +62,27 @@ NMI_MASK = 0x80000000
 #define ORIG_RAX 120       /* + error_code */ 
 #define EFLAGS 144
 
+
+/* Macros */
+.macro zeroentry sym
+	movq (%rsp),%rcx
+	movq 8(%rsp),%r11
+	addq $0x10,%rsp /* skip rcx and r11 */
+	pushq $0	/* push error code/oldrax */
+	pushq %rax	/* push real oldrax to the rdi slot */
+	leaq  \sym(%rip),%rax
+	jmp error_entry
+.endm
+
+.macro errorentry sym
+	movq (%rsp),%rcx
+	movq 8(%rsp),%r11
+	addq $0x10,%rsp /* rsp points to the error code */
+	pushq %rax
+	leaq  \sym(%rip),%rax
+	jmp error_entry
+.endm
+
 .macro SAVE_REST
 	subq $6*8,%rsp
 	movq %rbx,5*8(%rsp)
@@ -79,7 +116,6 @@ NMI_MASK = 0x80000000
 	addq $9*8+8,%rsp
 .endm	
 
-
 .macro HYPERVISOR_IRET flag
 	testl $NMI_MASK,2*8(%rsp)
 	jnz   2f
@@ -98,6 +134,8 @@ NMI_MASK = 0x80000000
 	jmp  hypercall_page + (__HYPERVISOR_iret * 32)
 .endm
 
+
+
 /*
  * Exception entry point. This expects an error code/orig_rax on the stack
  * and the exception handler in %rax.	
@@ -130,73 +168,24 @@ error_call_handler:
 	call *%rax
 	jmp error_exit
 
-.macro zeroentry sym
-	movq (%rsp),%rcx
-	movq 8(%rsp),%r11
-	addq $0x10,%rsp /* skip rcx and r11 */
-	pushq $0	/* push error code/oldrax */ 
-	pushq %rax	/* push real oldrax to the rdi slot */ 
-	leaq  \sym(%rip),%rax
-	jmp error_entry
-.endm	
-
-.macro errorentry sym
-	movq (%rsp),%rcx
-	movq 8(%rsp),%r11
-	addq $0x10,%rsp /* rsp points to the error code */
-	pushq %rax
-	leaq  \sym(%rip),%rax
-	jmp error_entry
-.endm
-
-#define XEN_GET_VCPU_INFO(reg)	movq HYPERVISOR_shared_info,reg
-#define XEN_PUT_VCPU_INFO(reg)
-#define XEN_PUT_VCPU_INFO_fixup
-#define XEN_LOCKED_BLOCK_EVENTS(reg)	movb $1,evtchn_upcall_mask(reg)
-#define XEN_LOCKED_UNBLOCK_EVENTS(reg)	movb $0,evtchn_upcall_mask(reg)
-#define XEN_TEST_PENDING(reg)	testb $0xFF,evtchn_upcall_pending(reg)
-
-#define XEN_BLOCK_EVENTS(reg)	XEN_GET_VCPU_INFO(reg)			; \
-                    			XEN_LOCKED_BLOCK_EVENTS(reg)	; \
-    				            XEN_PUT_VCPU_INFO(reg)
-
-#define XEN_UNBLOCK_EVENTS(reg)	XEN_GET_VCPU_INFO(reg)			; \
-                				XEN_LOCKED_UNBLOCK_EVENTS(reg)	; \
-    			            	XEN_PUT_VCPU_INFO(reg)
-
 
 
 ENTRY(hypervisor_callback)
 	zeroentry hypervisor_callback2
 
 ENTRY(hypervisor_callback2)
-	movq %rdi, %rsp 
+	movq %rdi, %rsp
 11:	movq %gs:8,%rax
 	incl %gs:0
 	cmovzq %rax,%rsp
 	pushq %rdi
-	call do_hypervisor_callback 
+	call do_hypervisor_callback
 	popq %rsp
 	decl %gs:0
-	jmp error_exit
-
-restore_all_enable_events:  
-	XEN_UNBLOCK_EVENTS(%rsi)        # %rsi is already set up...
-
-scrit:	/**** START OF CRITICAL REGION ****/
-	XEN_TEST_PENDING(%rsi)
-	jnz  14f			# process more events if necessary...
-	XEN_PUT_VCPU_INFO(%rsi)
-	RESTORE_ALL
-	HYPERVISOR_IRET 0
-
-14:	XEN_LOCKED_BLOCK_EVENTS(%rsi)
-	XEN_PUT_VCPU_INFO(%rsi)
-	SAVE_REST
-	movq %rsp,%rdi                  # set the argument again
-	jmp  11b
-ecrit:  /**** END OF CRITICAL REGION ****/
 
+error_exit:
+	RESTORE_REST
+	XEN_BLOCK_EVENTS(%rsi)
 
 retint_kernel:
 retint_restore_args:
@@ -211,11 +200,22 @@ retint_restore_args:
 	RESTORE_ALL
 	HYPERVISOR_IRET 0
 
+restore_all_enable_events:
+	XEN_UNBLOCK_EVENTS(%rsi)        # %rsi is already set up...
 
-error_exit:
-	RESTORE_REST
-	XEN_BLOCK_EVENTS(%rsi)		
-	jmp retint_kernel
+scrit:	/**** START OF CRITICAL REGION ****/
+	XEN_TEST_PENDING(%rsi)
+	jnz  14f			# process more events if necessary...
+	XEN_PUT_VCPU_INFO(%rsi)
+	RESTORE_ALL
+	HYPERVISOR_IRET 0
+
+14:	XEN_LOCKED_BLOCK_EVENTS(%rsi)
+	XEN_PUT_VCPU_INFO(%rsi)
+	SAVE_REST
+	movq %rsp,%rdi                  # set the argument again
+	jmp  11b
+ecrit:  /**** END OF CRITICAL REGION ****/
 
 
 
-- 
1.7.7.6